1. Field of the Invention
The present invention is related to a turbocharged internal combustion engine in which the compressor section of the turbocharger has more than one air inlet.
2. Disclosure Information
Turbocharging has been in use for many years with internal combustion engines. Recent requirements for reduced exhaust emissions, coupled with an increased demand for better fuel economy, have rendered turbocharging more important than ever. Designers of contemporary turbochargers are faced with a myriad of challenges. One of the challenges relates to the sizing of the turbocharger, inasmuch as a larger turbocharger, may be required to provide enough air to operate an engine efficiently at a variety of operating conditions, such as at high altitude. A problem arises, however, if the turbocharger compressor section is too large physically, because this generally increases the amount of time required for the turbocharger to increase rotational speed and, therefore, mass throughput, in response to a command for more engine torque. Thus, so called “turbo lag” may ensue. A current solution favors the application of two turbochargers of smaller size. This, however, greatly increases cost, complexity and packaging concerns.
Most known automotive turbochargers use a single turbine and a single compressor attached to a single shaft. However, it has been determined that two compressor wheels may be attached back to back and indeed, combined into a single piece, with the result being that the performance of the turbocharger is enhanced with a single turbocharging unit.
It would be desirable to provide an air system for a turbocharged engine having more than one compressor element on a single shaft, while minimizing the amount of air system plumbing hardware under the hood of the vehicle, so as to make the engine air system both compact and efficient.